Study of Parity Non-conservation Phenomena in Rare-earth Atoms

这项研究的目的是测量稀土原子在大范围同位素范围内的紧靠相反宇称能级对的宇称混合，并检验电弱标准模型以外的各种理论模型。1995-1997财政年度取得的成果如下1.对新型环形染料和钛/蓝宝石激光器的绝对波长进行了从可见光到红外的标定。利用RB-D2谱线的饱和吸收和调频光谱信号对激光器进行了稳定，绝对频率漂移由几百MHz/h提高到0.7 MHz/h。在大型真空室中新安装了原子束炉、静电电极和电磁铁，并编制了CAMAC接口模块和软件来控制电磁场和激光偏振的方向。经过综合测试，整个系统运行良好，原子束稳定持续时间提高到70小时。利用该系统系统地测量了Sm、Pr和Tm原子的超精细结构、同位素位移和塞曼-斯塔克效应，得到了精确的光谱数据。特别是在Smi能级，观察到了较大的Stark分裂，首次发现了张量极化率与同位素的明显依赖关系。上述结果发表在日本物理学会会议上的16篇口头报告、国际会议上的4篇报告、科学期刊上的8篇文章、广岛大学理工学院的5篇硕士论文和3篇博士论文中。

The purpose of this study is to measure the parity mixing of close-lying opposite-parity level pairs of rare earth atoms over wide range of isotopes and to inspect various theoretical models beyond the electroweak standard model. The obtained results during 1995-1997 fiscal years are described in the following.1. The absolute wavelengths of the new ring dye and Ti/Sapphire lasers were calibrated from visible to infrared region. The laser was stabilized with the signal from saturated-absorption and frequency-modulated spectroscopies of Rb-D2 line, and the absolute frequency drift was improved from several hundred MHz/h to 0.7MHz/h.2. The atomic-beam oven, electrostatic electrodes and electromagnet were newly installed in large-size vauum chamber, and CAMAC interface module & software were prepared to control the directions of electromagnetic fields and laser polarization. As a result of general tests, the whole system was operated well and the duration time of stable atomic beam was improved to 70 hours.3. By using the above system, hyperfine structures, isotope shifts and Zeeman-Stark effects were systematically measured for many close-lying opposite-parity level pairs of Sm, Pr and Tm atoms, and precise spectroscopic data were obtained. Particularly in a level of Sm I,large Stark splitting was observed, and clear isotope dependence of the tensor polarizability was found for the first time.4. The above results were published in 16 oral presentaitons in the meetings of Japanese Physical Society, 4 presentations in international conferences, 8 articles in the scientific journals, 5 master and 3 doctoral theses in the Faculty of Science, Hiroshima university.